Cyclic sciatica associated with contralateral endometrioma: a case report and discussion

T2-weighted image (TR: 4000, TE: 105) shows a cystic mass (arrow) with heterogeneous hyperintense signals in the posterior sacral area, pushing the uterus against the sciatic nerve (arrowhead) in the left sciatic notch (A, axial view; B, coronal view) during her menstrual period. After menstruation the cystic mass became an irregular smaller mass (arrow) with hyperintense signals (D, axial view), and the uterus returned to the midline position of pelvic cavity (C, coronal view).